This invention concerns car wash brushes and more particularly horizontal top brushes which extend across the top of a car or vertical side brushes which are positioned on each side of the car body. These brushes are rotated as they pass over the upper or side surfaces of a car body as it transmits through the car wash tunnel to effect cleaning of these surfaces. The top brush is mounted on a counterweighted frame which pivots to allow the rotating top brush to move up and down as the brush contacts the various vehicle surfaces, with a preset contact pressure exerted by an adjustment of the counterweighting. Such top and side brushes have in the past used closed cell foam fingers which are long and flaccid. Washing is achieved by a scrubbing action carried out by the tips of the fingers which are held extended by rotation of the brush core at a relatively high speed, i.e., in excess of 100 rpm, with the long length and speed of rotation creating sufficient centrifugal force to hold the tips out stiffly to create adequate scrubbing pressure without folding of the fingers.
The tips must be held extended out to develop proper scrubbing pressure, since if the fingers bend over, scrubbing pressure is substantially compromised. Thus, a high speed rotation and a large brush diameter (50 inches or larger) is required to create the level of centrifugal force acting on the fingers necessary to achieve this result.
In prior designs, such top brushes have had a constant diameter core from which the foam brush fingers extend radially. The brush core in the prior top brush designs were of a relatively small diameter, i.e., 10 inches, since car antennas would be bent too far when the brush passes over the same if the cores were of a substantially greater diameter. The long flaccid fingers which are extended by rotation at a relatively high speed, define a space for the antenna to pass through without excessive bending of the antenna.
The prior top brushes sometimes create difficulties when the small diameter core encounters a sharply vertical surface vehicle when the brush is not rotating as when a vehicle is driven through the wash tunnel without the equipment operating or when the brush is not rotating because of an equipment failure since the small diameter core will often wedge against such a surface, stopping the vehicle or breaking the brush or frame.
The high speed rotation of the fingers in both the top and side brushes create the possibility of vehicle damage by the fingers snagging some feature on a washed vehicle exterior.
Another difficulty concerns the possibility of the brush fingers of a top brush descending completely down into the bed of a pickup, kicking up debris collecting in the bed as the long fingers held out by centrifugal force reach down into every crevice of the bed. The long fingers straddle the side rails and allow the brush to descend to create contact with the bed bottom.
It is the object of the present invention to provide a car wash brush construction for both top and side brushes which does not require rotation at high speed.
It is another object to provide a top brush which avoids jamming of a top brush core when encountering a vertical or sharply inclined surface of a vehicle being washed when the brush is not rotated, and also does not contact the bottoms of pickup truck beds.